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Understanding weights in order to tow your RV safely!

Understanding the meaning of the weights for your RV, will help you do a variety of things from buying the right tow vehicle to navigating sandy tracks, even crossing a precarious bridge or two. So hopefully this will help you get your head around the different ways to measure weights and what all these words and acronyms actually mean.

Tare mass

This is mass of the caravan delivered by the factory including all factory fitted options but excluding liquids such as water and gas.

Payload

Payload is a set weight dictated by the RV manufacturer. To find out what this is one your RV subtract the Tare weight from the ATM (Aggregate Trailer Mass) and this is the maximum permissible loading for your RV. Any additional aftermarket accessories are counted as part of the RV’s payload.

ATM (Aggregate trailer mass)

This is the maximum your RV is allowed to weigh and is set by the manufacturer. Put simply, this is your RV’s tare weight plus it’s maximum permissible loading weight. You shouldn’t exceed this weight in any way.

Aggregate trailer mass = tare mass (empty trailer) + max payload

GTM (Gross Trailer Mass)

This is the maximum amount load that can be supported by the RV wheels excluding the weight supported by your car (or jockey wheel). This set by the manufacture and should not be exceeded in any way.

Gross trailer mass = Aggregate trailer mass – Tow ball mass

Tow Ball Mass

This is the portion of the trailer mass that is taken by the rear of your tow vehicle when you are hitched up. It is important to remember that loading a trailer unevenly can cause dramatic changes to your tow ball mass, you need be wary of how you pack and don’t overload particular parts of your caravan. Tow Ball Mass is important to know as it will help you select the right tow vehicle or have your existing one equipped to suit.

If you require further information or clarification on these weights please feel free to contact your local Jayco Dealer.